[24] Mineral wells, of various qualities, are found in almost every part of the island. As an instance of the hot wells, the following account of those found in Cheribon is selected. "At the village of _Bongas_ (situated about ten miles to the north-east of _Karang-Sambong_) I directed my route to the large mountain, in order to examine part of the hills along its foot, called the hills of _Pana-wangan_, and several hot wells which are found near their borders. On approaching these hills, after a very gentle acclivity covered entirely by calcareous stones, I very soon came to the spot of the hot wells. They are found on a gently inclining plain, about one hundred yards in circumference. This plain is perfectly white; and on approaching it, it is perceived at some distance by a sulphureous vapour, arising from the whole neighbourhood. The water springs from several apertures, but their temperatures are not equal; the hottest indicates the degree of one hundred and thirty of Fahrenheit's scale. They all contain a very large quantity of calcareous earth in solution and suspension, which coming into contact with the air, immediately separates, and adheres to the surrounding objects, or is precipitated to the ground. The branches of the shrubs in the vicinity are all enveloped by a stalactical incrustation. The water from the different wells gently descending the white calcareous plain, is collected in a rivulet below. A large number of calcareous rocks are found in the vicinity of the plains; some are covered with elegant crystals of calcareous spar, others have a coralline appearance, and some have the fracture of alabaster. On proceeding up the hills, immense irregular blocks of calcareous rocks are found strewed about in the valleys. About one hundred yards above this district are several wells of naphtha, or petroleum. It rises in small plashes of water, about twelve or eighteen inches in diameter, upon which it drives its black specks, emitting the peculiar odour of the petroleum. The earth in the circumference of these plashes is strongly impregnated with this oil: it is very tough, and from that immediately bounding apertures, the naphtha flows out on its being pressed; some portions exactly resemble asphaltum. A considerable space of ground is occupied by these wells. The stones are all calcareous. A few hundred yards above this spot, the borders of the hills become very steep. I examined them to some extent. They are composed exclusively of calcareous stones. Several extensive stalactitic caves are found at no great distance above the wells; they exhibit the usual appearances of calcareous caves and vaults. The process of incrustation is continually going on. In some places, deep perforations extend into the heart of the hills."--_Essay on the Mineralogy of Java, by Dr. Horsfield. Bat. Trans._ vol. ix.